Double check valve device



July 25, 1933. E. E, HEWlTT 1,919,430

- EOUBLE CHECK VALVE DEVICE Filed Aug. 15, 1929 ELLIS E HEWITT ATTORNEY Patented `luly 25, 1933 UNITED STATES PATENT orFicE ELLIS E. HEVITT, OF EDG-EWOOI), PENNSYLVANIA, ASSIGNOR TO THE WESTINGIIOUSE AIR BRAKE COMPANY, OF WILMERDING, PENNSYLVANIA, A CORPORATION 0F' PENNSYLVANIA DOUBLE CI-IECK VALVE DEVICE Application filed .August 13,

This invention relates to fluid pressure actuated valve devices and more particularly to a double check valve device adapted to control the flow of fluid under pressure between either one of two separate pipes and a third pipe.

The principal object of my invention is to provide an improved valve device of th above character. Y

In the accompanying drawing; Figure 1 is a sectional view of a double check valve device constructed in accordance with my invention; and Fig. 2 is a sectional view taken on the line 2 2 of Fig. 1. K

As shown in the drawing, the double check valve device comprises a casing having a hollow body portion 1 and a cover plate 2 secured to one end of the body portion by a plurality of screws 3.

Removably mounted in the body portion 1 is a valve assembly comprising a cage 4 having a transversely disposed wall 5, which forms chambers 6 and 7. These chambers are connected by a bore 8 through the wall 5. The bore 8 is connected by means of a plus rality of passages 9 with a cavity 10, which surrounds the cage 4.

Contained in chamber 6 is a valve 11 provided with a plurality of projections 12, which engage the wall oi said chamber and guide the valve. Between said projections are passages 13 through which communication is established from one side of the valve to the opposite side thereof.

The valve 11 is provided on one side with a recess containing a seal 14, which is adapted to engage a seat rib 21, formed concentric with the bore 8 in wall 5, so as to eliect a leal; proof seal between chamber G and bore 8.

Contained in chamber 7 is a valve 15, which may be similar in construction to valve 11. The valve 15 is provided with a plurality of projections 16, which engage the wall of chamber 7 and guide the valve. Between the projections 16 are passages 17 through which communication is established from one side of the valve to the other side thereof.

The valve 15 is provided on one side with a recess containing a seal 18, which is adapt- 1929. Serial No.V 385,528.

ed to engage a seat rib 19 ormedconcentric with the bore 8 in wall 5, so as to effect a leak proof seal between chamber 7 and bore 8.V

The valves 1l and 15 are connected together by a `stem 2O having an enlarged centhrough a bore in valve lland is provided with a nut 23 at its outerA end, said nut havlng screw-threaded engagement on said eX- Vtension to hold the valve against stem 20.

Likewise, an extension 24 at the opposite end of stem `2O extends through a central bore in valve 15 'and a nut 25 is provided thereon to hold said valve in engagement with stem 20. v,

Interposed between the right end of the cage 4 and a shoulder 26 in the body portion 1 is a compressible gasket 27, while interposed between the lift end of the cage 4 and cover plate 2, and the cover plate and body portion 1 is a compressible gasket 28, said gaskets being compressed when the device is assembled' and the screws 3 are in the tightened position, as shown in the drawing. By these means, a leali proof seal is eiected between chamber 6 and chamber 10, and chamber 7 and chamber 10.

A pipe 29 is connected to chamber 10 and in operation, the connected valves 11 and 15 are adapted at one time to allow a communication between a ypipe 30 connected to chamber 6 and the pipel 29, and at another time said valves are adapted to allow a communication between a pipe 81, connected to cham# ber 7, and the pipe 29, as will now be eX- plained.

In order to connect pipe 31 to pipe 29, liuid under pressure may be supplied to valveV chamber 6 through pipe 30, and with pipe 31 and valve chamber 7 at substantially atmospheric pressure, the pressure of fluid in valve chamber 6, acting on the left side of valve 11, shifts said valve into engagement with seat rib ,21, thereby closing communication between chamber 6 and bore 8, and ati also shifts valve 11 away from seat rib 21,

so as to establish communication between pipe 30 and pipe 29 by way of chamber 6, passages 13 around valve 11, bore 8, passages 9 and chamber 10.

One particular feature of my invention is that the valve assembly, comprising the cage 4 and the contained valves is readily removable rom the casing by taking out ther screws 3 and removing the cover plate 2 from the body portion 1. This simplifies replaces ment of broken or worn parts and effects easier assembling of the valves in thecage. Furthermore, in suoli a construction only one cover plate is required, whereas if the cage 4 were in the Jform of a bushing pressed into the body portion, then a cover plate in the right side of the body 'portion wouldalso be required, since the valves would have to be initially separated from each other and then one removed through the left side of the body and the other removedthrough the right side of the body.

While one illustrative embodiment of the invention has been described in detail, it is not my intention to limit its scope .to that embodiment or otherwise than by the terms of the appended claims.

' Having now described my invention, what I claim as new and desire to secure by Letters Patent, is: c l

l. A double check valve device for controlling communication through a plurality of pipes, said check valve device comprising a casing having a body portion open at one side, a cover plate to close the opening in said body portion, a valve cage having a sliding fit in said casing, means for eiecting a lealtprooif seal between one end of said cage and the body portion and the other end of said cage and said cover plate, and valves operatively connected within said cage, said valves being insertable into or removable from said body portion only with said cage when said cover plate is removed.

2. A double check valve device for controlling communication through a` plurality of pipes, said check valve device comprising a hollow casing open at one end, a bushing removably mounted in said casing and forming an annular chamber between said bushing and casing, a cover plate for closing the open end of said casing, valves operatively mounted in said bushing and having a chamber at opposite sides, means interposed between one end of said bushing and the casing and the other end of said bushing and said cover plate for effecting a leak proof seal between each of thelast mentioned chambers and said annular chamber and a pipe connected to each of said chambers.

3. A double check valve device comprising a casing, avalve cage removably mounted in said casing, theA wall of said cage being spaced from the wall of said casing to provide an annular. chamber `which surrounds the valve cage, a pipe connected to said an-y nular chamber, a wall dividing the cage into two valve chambers, a pipe connected to each ofsaid valve chambers, seat ribs formed on the opposite sides of said wall, a. bore formed through said wall concentric withsaid seat ribs, openings connecting said annular chamber and said bore, and a valve in each valve chamber, said valves being connected to oper ate together, so that when one valve is seated, the other valve is unseated.

'4. Adouble check valve device, for controlling communication through a plurality of pipes, comprising a casing having a hollow body portion open at one end, a. cover plate to close the open end of said body portion, a valve assembly comprisingy a cage having a loose fit in said body portion, two oppositely disposed seat ribs within said cage`,'two connected valves within said cage adapted to engage said seat ribs, and means interposed between one end oit' said cage and the body portion of the casing and the other end of said cage and said cover plate for e'liecting a leakprooil seal.

ELLIS E. HEVITT. 1 

